Since joining Pinterest, I've noticed a lot of links to inspirational or humorous quotes displayed as graphics, sort of like digital posters. I suppose this trend has been building for a while, since the popularity of image macros started to take off. But I didn't really think about the consequences for semantics and search until I read this post by Kevin Marks: Facebook, Twitter and Google Plus shun HTML, causing the infographic plague.
I can understand the appeal of a pithy phrase turned into a poster-like graphic. I am also a fan of good design and typography. But a solid color rectangle with Arial block letters made in MS Paint? Really, that doesn't convey anything that actual text can't.
And yet, the current structure of some social media (Twitter being a notable exception) makes it worthwhile to put text into images, instead of using actual text.